Effect of angiotensin blockade on the association between albuminuria and peripheral arterial disease in elderly Taiwanese patients with type 2 diabetes mellitus

Background: The aim of the present study was to examine the impact of the clinical use of angiotensin-converting enzyme inhibitors (ACEI) or angiotensin receptor blockers (ARB) on the association between the urinary albumin/creatinine ratio (ACR) and ankle-brachial index (ABI) or peripheral arterial disease (PAD) in elderly Taiwanese patients with type 2 diabetes mellitus. Methods and Results: Two-hundred and ninety patients (108 men, 182 women) aged ≥65 years (mean±SD, 71.6±4.9) were cross-sectionally studied. ACR was expressed as the natural logarithm [ln(ACR)] and divided into normoalbuminuria (<30.0 g/mg) and albuminuria (≥30.0 g/mg). ABI was evaluated both continuously and as peripheral arterial disease (PAD)(-) and PAD(+) using the cutoff of 0.9. Statistical analyses were performed with consideration of covariates and the use of ACEI/ARB. Results showed that in patients not using ACEI/ARB, ln (ACR) negatively correlated with ABI (r=-0.261, p<0.01) and was associated with ABI with adjusted regression coefficient of -0.0213 (p<0.05). PAD patients had a significantly higher level of ln(ACR) than those without PAD (4.83±1.34 vs 3.73±1.29, p<0.001) and PAD prevalence was significantly higher in those with albuminuria than in those with normoalbuminuria (22.6% vs 4.9%, p<0.001). The multivariate-adjusted odds ratio for PAD for every 1 unit increment of ln (ACR) was 2.10 (1.31-3.38), and for albuminuria vs normoalbuminuria 3.86 (1.04-14.31) in patients not using ACEI/ARB. In patients using ACEI/ARB, none of these analyses was significant. Patients using ACEI/ARB had a significantly lower risk of PAD with a multivariate-adjusted odds ratio of 0.34 (0.12-0.97). Conclusions: ACR negatively correlates with ABI and is associated with PAD in elderly diabetic patients not treated with ACEI/ARB. The use of ACEI/ARB attenuates this association and may be associated with a lower risk of PAD.